Tasmota/lib/libesp32_div/esp-nimble-cpp/src/NimBLEL2CAPChannel.cpp
2025-06-15 18:24:54 +02:00

315 lines
10 KiB
C++

//
// (C) Dr. Michael 'Mickey' Lauer <mickey@vanille-media.de>
//
#include "NimBLEL2CAPChannel.h"
#if CONFIG_BT_ENABLED && CONFIG_BT_NIMBLE_L2CAP_COC_MAX_NUM
# include "NimBLEClient.h"
# include "NimBLELog.h"
# include "NimBLEUtils.h"
# if defined(CONFIG_NIMBLE_CPP_IDF)
# include "host/ble_gap.h"
# else
# include "nimble/nimble/host/include/host/ble_gap.h"
# endif
// L2CAP buffer block size
# define L2CAP_BUF_BLOCK_SIZE (250)
# define L2CAP_BUF_SIZE_MTUS_PER_CHANNEL (3)
// Round-up integer division
# define CEIL_DIVIDE(a, b) (((a) + (b) - 1) / (b))
# define ROUND_DIVIDE(a, b) (((a) + (b) / 2) / (b))
// Retry
constexpr uint32_t RetryTimeout = 50;
constexpr int RetryCounter = 3;
NimBLEL2CAPChannel::NimBLEL2CAPChannel(uint16_t psm, uint16_t mtu, NimBLEL2CAPChannelCallbacks* callbacks)
: psm(psm), mtu(mtu), callbacks(callbacks) {
assert(mtu); // fail here, if MTU is too little
assert(callbacks); // fail here, if no callbacks are given
assert(setupMemPool()); // fail here, if the memory pool could not be setup
NIMBLE_LOGI(LOG_TAG, "L2CAP COC 0x%04X initialized w/ L2CAP MTU %i", this->psm, this->mtu);
};
NimBLEL2CAPChannel::~NimBLEL2CAPChannel() {
teardownMemPool();
NIMBLE_LOGI(LOG_TAG, "L2CAP COC 0x%04X shutdown and freed.", this->psm);
}
bool NimBLEL2CAPChannel::setupMemPool() {
const size_t buf_blocks = CEIL_DIVIDE(mtu, L2CAP_BUF_BLOCK_SIZE) * L2CAP_BUF_SIZE_MTUS_PER_CHANNEL;
NIMBLE_LOGD(LOG_TAG, "Computed number of buf_blocks = %d", buf_blocks);
_coc_memory = malloc(OS_MEMPOOL_SIZE(buf_blocks, L2CAP_BUF_BLOCK_SIZE) * sizeof(os_membuf_t));
if (_coc_memory == 0) {
NIMBLE_LOGE(LOG_TAG, "Can't allocate _coc_memory: %d", errno);
return false;
}
auto rc = os_mempool_init(&_coc_mempool, buf_blocks, L2CAP_BUF_BLOCK_SIZE, _coc_memory, "appbuf");
if (rc != 0) {
NIMBLE_LOGE(LOG_TAG, "Can't os_mempool_init: %d", rc);
return false;
}
auto rc2 = os_mbuf_pool_init(&_coc_mbuf_pool, &_coc_mempool, L2CAP_BUF_BLOCK_SIZE, buf_blocks);
if (rc2 != 0) {
NIMBLE_LOGE(LOG_TAG, "Can't os_mbuf_pool_init: %d", rc);
return false;
}
this->receiveBuffer = (uint8_t*)malloc(mtu);
if (!this->receiveBuffer) {
NIMBLE_LOGE(LOG_TAG, "Can't malloc receive buffer: %d, %s", errno, strerror(errno));
return false;
}
return true;
}
void NimBLEL2CAPChannel::teardownMemPool() {
if (this->callbacks) {
delete this->callbacks;
}
if (this->receiveBuffer) {
free(this->receiveBuffer);
}
if (_coc_memory) {
free(_coc_memory);
}
}
int NimBLEL2CAPChannel::writeFragment(std::vector<uint8_t>::const_iterator begin, std::vector<uint8_t>::const_iterator end) {
auto toSend = end - begin;
if (stalled) {
NIMBLE_LOGD(LOG_TAG, "L2CAP Channel waiting for unstall...");
NimBLETaskData taskData;
m_pTaskData = &taskData;
NimBLEUtils::taskWait(taskData, BLE_NPL_TIME_FOREVER);
m_pTaskData = nullptr;
stalled = false;
NIMBLE_LOGD(LOG_TAG, "L2CAP Channel unstalled!");
}
struct ble_l2cap_chan_info info;
ble_l2cap_get_chan_info(channel, &info);
// Take the minimum of our and peer MTU
auto mtu = info.peer_coc_mtu < info.our_coc_mtu ? info.peer_coc_mtu : info.our_coc_mtu;
if (toSend > mtu) {
return -BLE_HS_EBADDATA;
}
auto retries = RetryCounter;
while (retries--) {
auto txd = os_mbuf_get_pkthdr(&_coc_mbuf_pool, 0);
if (!txd) {
NIMBLE_LOGE(LOG_TAG, "Can't os_mbuf_get_pkthdr.");
return -BLE_HS_ENOMEM;
}
auto append = os_mbuf_append(txd, &(*begin), toSend);
if (append != 0) {
NIMBLE_LOGE(LOG_TAG, "Can't os_mbuf_append: %d", append);
return append;
}
auto res = ble_l2cap_send(channel, txd);
switch (res) {
case 0:
NIMBLE_LOGD(LOG_TAG, "L2CAP COC 0x%04X sent %d bytes.", this->psm, toSend);
return 0;
case BLE_HS_ESTALLED:
stalled = true;
NIMBLE_LOGD(LOG_TAG, "L2CAP COC 0x%04X sent %d bytes.", this->psm, toSend);
NIMBLE_LOGW(LOG_TAG,
"ble_l2cap_send returned BLE_HS_ESTALLED. Next send will wait for unstalled event...");
return 0;
case BLE_HS_ENOMEM:
case BLE_HS_EAGAIN:
case BLE_HS_EBUSY:
NIMBLE_LOGD(LOG_TAG, "ble_l2cap_send returned %d. Retrying shortly...", res);
os_mbuf_free_chain(txd);
ble_npl_time_delay(ble_npl_time_ms_to_ticks32(RetryTimeout));
continue;
default:
NIMBLE_LOGE(LOG_TAG, "ble_l2cap_send failed: %d", res);
return res;
}
}
NIMBLE_LOGE(LOG_TAG, "Retries exhausted, dropping %d bytes to send.", toSend);
return -BLE_HS_EREJECT;
}
# if CONFIG_BT_NIMBLE_ROLE_CENTRAL
NimBLEL2CAPChannel* NimBLEL2CAPChannel::connect(NimBLEClient* client,
uint16_t psm,
uint16_t mtu,
NimBLEL2CAPChannelCallbacks* callbacks) {
if (!client->isConnected()) {
NIMBLE_LOGE(
LOG_TAG,
"Client is not connected. Before connecting via L2CAP, a GAP connection must have been established");
return nullptr;
};
auto channel = new NimBLEL2CAPChannel(psm, mtu, callbacks);
auto sdu_rx = os_mbuf_get_pkthdr(&channel->_coc_mbuf_pool, 0);
if (!sdu_rx) {
NIMBLE_LOGE(LOG_TAG, "Can't allocate SDU buffer: %d, %s", errno, strerror(errno));
return nullptr;
}
auto rc = ble_l2cap_connect(client->getConnHandle(), psm, mtu, sdu_rx, NimBLEL2CAPChannel::handleL2capEvent, channel);
if (rc != 0) {
NIMBLE_LOGE(LOG_TAG, "ble_l2cap_connect failed: %d", rc);
}
return channel;
}
# endif // CONFIG_BT_NIMBLE_ROLE_CENTRAL
bool NimBLEL2CAPChannel::write(const std::vector<uint8_t>& bytes) {
if (!this->channel) {
NIMBLE_LOGW(LOG_TAG, "L2CAP Channel not open");
return false;
}
struct ble_l2cap_chan_info info;
ble_l2cap_get_chan_info(channel, &info);
auto mtu = info.peer_coc_mtu < info.our_coc_mtu ? info.peer_coc_mtu : info.our_coc_mtu;
auto start = bytes.begin();
while (start != bytes.end()) {
auto end = start + mtu < bytes.end() ? start + mtu : bytes.end();
if (writeFragment(start, end) < 0) {
return false;
}
start = end;
}
return true;
}
// private
int NimBLEL2CAPChannel::handleConnectionEvent(struct ble_l2cap_event* event) {
channel = event->connect.chan;
struct ble_l2cap_chan_info info;
ble_l2cap_get_chan_info(channel, &info);
NIMBLE_LOGI(LOG_TAG,
"L2CAP COC 0x%04X connected. Local MTU = %d [%d], remote MTU = %d [%d].",
psm,
info.our_coc_mtu,
info.our_l2cap_mtu,
info.peer_coc_mtu,
info.peer_l2cap_mtu);
if (info.our_coc_mtu > info.peer_coc_mtu) {
NIMBLE_LOGW(LOG_TAG, "L2CAP COC 0x%04X connected, but local MTU is bigger than remote MTU.", psm);
}
auto mtu = info.peer_coc_mtu < info.our_coc_mtu ? info.peer_coc_mtu : info.our_coc_mtu;
callbacks->onConnect(this, mtu);
return 0;
}
int NimBLEL2CAPChannel::handleAcceptEvent(struct ble_l2cap_event* event) {
NIMBLE_LOGI(LOG_TAG, "L2CAP COC 0x%04X accept.", psm);
if (!callbacks->shouldAcceptConnection(this)) {
NIMBLE_LOGI(LOG_TAG, "L2CAP COC 0x%04X refused by delegate.", psm);
return -1;
}
struct os_mbuf* sdu_rx = os_mbuf_get_pkthdr(&_coc_mbuf_pool, 0);
assert(sdu_rx != NULL);
ble_l2cap_recv_ready(event->accept.chan, sdu_rx);
return 0;
}
int NimBLEL2CAPChannel::handleDataReceivedEvent(struct ble_l2cap_event* event) {
NIMBLE_LOGD(LOG_TAG, "L2CAP COC 0x%04X data received.", psm);
struct os_mbuf* rxd = event->receive.sdu_rx;
assert(rxd != NULL);
int rx_len = (int)OS_MBUF_PKTLEN(rxd);
assert(rx_len <= (int)mtu);
int res = os_mbuf_copydata(rxd, 0, rx_len, receiveBuffer);
assert(res == 0);
NIMBLE_LOGD(LOG_TAG, "L2CAP COC 0x%04X received %d bytes.", psm, rx_len);
res = os_mbuf_free_chain(rxd);
assert(res == 0);
std::vector<uint8_t> incomingData(receiveBuffer, receiveBuffer + rx_len);
callbacks->onRead(this, incomingData);
struct os_mbuf* next = os_mbuf_get_pkthdr(&_coc_mbuf_pool, 0);
assert(next != NULL);
res = ble_l2cap_recv_ready(channel, next);
assert(res == 0);
return 0;
}
int NimBLEL2CAPChannel::handleTxUnstalledEvent(struct ble_l2cap_event* event) {
if (m_pTaskData != nullptr) {
NimBLEUtils::taskRelease(*m_pTaskData, event->tx_unstalled.status);
}
NIMBLE_LOGI(LOG_TAG, "L2CAP COC 0x%04X transmit unstalled.", psm);
return 0;
}
int NimBLEL2CAPChannel::handleDisconnectionEvent(struct ble_l2cap_event* event) {
NIMBLE_LOGI(LOG_TAG, "L2CAP COC 0x%04X disconnected.", psm);
channel = NULL;
callbacks->onDisconnect(this);
return 0;
}
/* STATIC */
int NimBLEL2CAPChannel::handleL2capEvent(struct ble_l2cap_event* event, void* arg) {
NIMBLE_LOGD(LOG_TAG, "handleL2capEvent: handling l2cap event %d", event->type);
NimBLEL2CAPChannel* self = reinterpret_cast<NimBLEL2CAPChannel*>(arg);
int returnValue = 0;
switch (event->type) {
case BLE_L2CAP_EVENT_COC_CONNECTED:
returnValue = self->handleConnectionEvent(event);
break;
case BLE_L2CAP_EVENT_COC_DISCONNECTED:
returnValue = self->handleDisconnectionEvent(event);
break;
case BLE_L2CAP_EVENT_COC_ACCEPT:
returnValue = self->handleAcceptEvent(event);
break;
case BLE_L2CAP_EVENT_COC_DATA_RECEIVED:
returnValue = self->handleDataReceivedEvent(event);
break;
case BLE_L2CAP_EVENT_COC_TX_UNSTALLED:
returnValue = self->handleTxUnstalledEvent(event);
break;
default:
NIMBLE_LOGW(LOG_TAG, "Unhandled l2cap event %d", event->type);
break;
}
return returnValue;
}
#endif // #if CONFIG_BT_ENABLED && CONFIG_BT_NIMBLE_L2CAP_COC_MAX_NUM